A comprehensive study of beryllium diffusion in InGaAs using different forms ofkick-out mechanism

Be diffusion during post-growth annealing has been investigated in InGaAs epitaxial layers. Kick-out mechanisms considering species charges, built-in electric field and Fermi-level effect have been studied. Several forms of kick-out mechanism have been implemented in our simulation programs. Experimental concentration profiles obtained by SIMS analysis have been compared systematically with the numerical results of simulations. We have deduced that the kick-out mechanism Be-i(0) double left right arrow Be-s(-) + I-III(+) is the dominating diffusion mechanism in InGaAs under our experimental conditions (Co = 3 x 19 cm(-3)) With our experimental data, we have found that the effective diffusion coefficient values are D = (7.7 - 9) x 10(-13) cm(2) s(-1) at T = 700 degrees C and D = (1.4-1.5) x 10(-11) cm(2) s(-1) at T = 800 degrees C which is several orders of magnitude higher than most published data. A possible explanation would be the effect of V/III flux ratio.